The present invention relates to an intermediate potential generation circuit, which is formed in a semiconductor integrated circuit device and generates an intermediate potential from a power source voltage applied to the device.
A conventional intermediate potential generation circuit formed in a semiconductor integrated circuit device has an arrangement shown in FIG. 1. Resistors R1 and R2 are series-connected between power sources Vcc and Vss to divide the power source voltage. Intermediate potential VR is obtained from a node between resistors R1 and R2. The Intermediate potential generating circuit is only used for an auxiliary circuit, and need not provide large current output. For this reason, the intermediate potential generation circuit of resistance division type shown in FIG. 1 meets the requirements of conventional semiconductor integrated circuit devices.
In recent large-scale semiconductor integrated circuit devices, however, an operation method thereof is complicated, and an intermediate potential generation circuit having a large current driving capacity is required. In addition, current consumption must be kept as low as possible. However, in the intermediate potential generation circuit shown in FIG. 1, if an output current is to be increased, a large current must flow from power source Vcc to source Vss. The current from source Vcc to source Vss must be, e.g., 10 times the output current. Therefore, current consumption is considerably increased.
Thus, in the conventional intermediate potential generation circuit shown in FIG. 1, both the requirements of large current driving capacity and lower current consumption cannot be satisfied at the same time.